Peter,
That’s unusual that a 2m cable works fine but a 5m doesn’t
USB2 signal performance is generally up to 5m before you start to lose signal voltage
I’m not guaranteeing the cable below , but I’ve seen quite a few folk ( eg: Astrobloke YouTube) use these USB2 active extension cables to resolve connectivity issues from Laptop to mount
They are not cheap but they have resolved many connectivity issues
All you need is one of these Startech “active extension cables” plus a 1m Startech USB2A to USB2 B cable from Laptop to mount
https://www.mwave.com.au/product/sta...ble-mf-ab68977
Maybe the ioptron mount has different characteristics than my SW mounts , however I do use 5m Startech Active USB3A to USB3B cables from my laptop to USB3 Active Hub at my mount ( at both my sites ) and never had a drop out
Cheers
Martin